The banks are that deal are Bank of America, Credit Suisse and Goldman Sachs. Those banks had been due to receive $110 million, according to filings, with the bulk of that sum contingent on a deal closing.

The Pfizer-Allergan and Halliburton-Baker Hughes deals may still come to fruition. Pfizer and Allergan could work out a new deal price, and Baker Hughes and Halliburton may find a way to divest more businesses than they initially planned.

But the two transactions highlight just how risky the M&A business has become, as regulators flex their muscles to hinder transactions that involve reducing taxes or competition.

The first quarter of 2016 saw $213.3 billion in withdrawn M&A, with Honeywell International’s proposed $102.8 billion bid for United Technologies the fourth largest withdrawn deal on record, according to Dealogic.